1. Field of the Invention
The present invention relates to a method for producing one-material optical fibers which consist of at least one light conducting core component supported by at least one support component within a protective casing or shell.
2. Prior Art
A particularly suitable light conducting fiber having a low attenuation is a single-material or one-material optical fiber, which is also known as dielectric rib waveguide or slab coupled waveguide. The one-material fiber consists of quartz which can be produced in a pure form and thus has a low optical attenuation.
One-material optical fibers are known which consist of a thin quartz carrier having a thickness of a few .mu.m and possess a rib-like enlargement which serves to conduct the light. In order to impart mechanical stability to this extremely fragile structure and to protect the surface of the conducting element from pollution, the structure is usually supported in a thicker quartz tube.
In the production of one-material optical fibers with a closed cross section, a blank having a similar shape but of a considerably larger cross section is produced. Since blanks with a closed cross section are difficult to manufacture, they are currently being assembled from a plurality of individual components, for example an outer tube, a thin supporting plate and a rod. After assemblying the blanks, they are subsequently heated and drawn to form the optical fibers. One-material optical fibers of the above described type are discussed in an article by P. Kaiser and H. W. Astle, "Low-Loss Single-Material Fibers Made From Pure Fused Silica", The Bell Systems Technical Journal, Vol. 53, No. 6, July-August 1974, pp. 1021-1039.